18
views
0
recommends
+1 Recommend
0 collections
    0
    shares
      • Record: found
      • Abstract: found
      • Article: found
      Is Open Access

      Analysis of Cellulose and Lignocellulose Materials by Raman Spectroscopy: A Review of the Current Status

      review-article

      Read this article at

          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

          Abstract

          This review is a summary of the Raman spectroscopy applications made over the last 10 years in the field of cellulose and lignocellulose materials. This paper functions as a status report on the kinds of information that can be generated by applying Raman spectroscopy. The information in the review is taken from the published papers and author’s own research—most of which is in print. Although, at the molecular level, focus of the investigations has been on cellulose and lignin, hemicelluloses have also received some attention. The progress over the last decade in applying Raman spectroscopy is a direct consequence of the technical advances in the field of Raman spectroscopy, in particular, the application of new Raman techniques (e.g., Raman imaging and coherent anti-Stokes Raman or CARS), novel ways of spectral analysis, and quantum chemical calculations. On the basis of this analysis, it is clear that Raman spectroscopy continues to play an important role in the field of cellulose and lignocellulose research across a wide range of areas and applications, and thereby provides useful information at the molecular level.

          Related collections

          Most cited references66

          • Record: found
          • Abstract: found
          • Article: not found

          Current characterization methods for cellulose nanomaterials

          Reliable characterization of cellulose nanomaterials is critical for their utilization in various applications. A new family of materials comprised of cellulose, cellulose nanomaterials (CNMs), having properties and functionalities distinct from molecular cellulose and wood pulp, is being developed for applications that were once thought impossible for cellulosic materials. Commercialization, paralleled by research in this field, is fueled by the unique combination of characteristics, such as high on-axis stiffness, sustainability, scalability, and mechanical reinforcement of a wide variety of materials, leading to their utility across a broad spectrum of high-performance material applications. However, with this exponential growth in interest/activity, the development of measurement protocols necessary for consistent, reliable and accurate materials characterization has been outpaced. These protocols, developed in the broader research community, are critical for the advancement in understanding, process optimization, and utilization of CNMs in materials development. This review establishes detailed best practices, methods and techniques for characterizing CNM particle morphology, surface chemistry, surface charge, purity, crystallinity, rheological properties, mechanical properties, and toxicity for two distinct forms of CNMs: cellulose nanocrystals and cellulose nanofibrils.
            Bookmark
            • Record: found
            • Abstract: found
            • Article: not found

            Elastic modulus and stress-transfer properties of tunicate cellulose whiskers.

            Experimental deformation micromechanics of natural cellulose fibers using Raman spectroscopy and X-ray diffraction have been widely reported. However, little has been published on the direct measurements of the mechanical properties, and in particular the elastic modulus, of the highly crystalline material in the native state. Here we report on measurements of the elastic modulus of tunicate cellulose using a Raman spectroscopic technique. A dispersed sample of the material is deformed using a four-point bending test, and a shift in a characteristic Raman band (located at 1095 cm(-1)) is used as an indication of the stress in the material. Relatively little intensity change of the Raman band located at 1095 cm(-1) is shown to occur for samples oriented parallel and perpendicular to the polarization direction of the laser, as compared to a highly oriented flax sample. This indicates that the tunicate sample is a two-dimensional in-plane random network of fibers. By use of this result, the Raman shift, and calibrations with strain from other materials, it is shown that the modulus of the material is very high, at about 143 GPa, and a lack of Raman band broadening is thought to be due to the fact that there is pure crystalline deformation occurring without the effect of crystalline/amorphous fractions. A strain sensitivity of the shift in the 1095-cm(-1) Raman peak for this specimen is shown to be -2.4 +/- 0.2 cm(-1)/%. A molecular mechanics approach, using computer simulation and an empirical force field, was used to predict the modulus of a highly oriented chain of the material, and this is found to be 145 GPa, which is in agreement with the experimental data. However, by use of a normal-mode analysis, it is found that a number of modes have positions close to the central positions of the experimental Raman band. One in particular is found to shift at a rate of 2.5 cm(-1)/%, but due to the complex nature of the structure, it is not entirely conclusive that this band is representative of the experimental findings.
              Bookmark
              • Record: found
              • Abstract: not found
              • Article: not found

              Multi-scale visualization and characterization of lignocellulosic plant cell wall deconstruction during thermochemical pretreatment

                Bookmark

                Author and article information

                Contributors
                Role: Academic Editor
                Journal
                Molecules
                Molecules
                molecules
                Molecules
                MDPI
                1420-3049
                27 April 2019
                May 2019
                : 24
                : 9
                : 1659
                Affiliations
                USDA, Forest Service, Forest Products Laboratory, Madison, WI 53726, USA; uagarwal@ 123456fs.fed.us
                Article
                molecules-24-01659
                10.3390/molecules24091659
                6539102
                31035593
                810a71c3-465c-49e9-929c-826d4a8b3ede
                © 2019 by the author.

                Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license ( http://creativecommons.org/licenses/by/4.0/).

                History
                : 04 March 2019
                : 26 April 2019
                Categories
                Review

                polymorphy,crystallinity,supramolecular structure,nanocellulose,nanocomposite,lignin,syringyl,hemicellulose,non-linear,density functional theory

                Comments

                Comment on this article